Valve means, particularly automatic waste gas valve means

ABSTRACT

A temperature-responsive valve operated by bimetallic means for exhausting waste gases from a burner. To reduce the noise level of the valve, the inner surface of the valve casing is tapered in the direction of flow and the flow is regulated by a plate which intersects the center axis of the casing and has its free edge disposed at substantially the same angle as the tapered surface. The plane free edge, cooperating with the tapered surface in the form of a circular segment, provides a highly advantageous relationship with respect to the production of sound. As the temperature of the flow increases, the flow area is increased, the arrangement being such that a small deflection of the plate effects a great increase in the flow area. In the preferred embodiment, the plate itself is bimetallic whereas in an alternate embodiment, the plate is displaced angularly by a bimetallic element. Where the clearance space between the plate and the casing is problematical with respect to noise generation, the plate may be made rectangular and the sides of the casing where the plate engages may be parallel to one another.

United States Patent 1191 Akesson 1 Jan. 1,1974

[ VALVE MEANS, PARTICULARLY AUTOMATIC WASTE GAS VALVE MEANS Stellan Akesson, Narvagen 28, Jonkoping, Sweden [22] Filed: Apr. 6, 1972 [211 Appl. No.: 241,626

[76] Inventor:

[56] References Cited UNITED STATES PATENTS 9/1956 Hill 12/1948 Krauss 2,673,687 3/1954 Alban et a1.

3,506,193 4/1970 Cole 236/93 3,664,582 5/1972 Jackson et al. 236/93 3228605 l/l966 Diermayer et al. 126/285 R Primary E.raminerWilliam E. Wayner Assistant E.raminerWilliam E. Tapolcal, Jr. Attorney-Dexter N. Shaw et al.

[57] ABSTRACT A temperature-responsive valve operated by bimetallic means for exhausting waste gases from a burner. To reduce the noise level of the valve, the inner surface of the valve casing is tapered in the direction of flow and the flow is regulated by a plate which intersects the center axis of the casing and has its free edge disposed at substantially the same angle as the tapered surface. The plane free edge, cooperating with the tapered surface in the form of a circular segment, provides a highly advantageous relationship with respect to the production of sound. As the temperature of the flow increases, the flow area is increased, the arrangement being such that a small deflection of the plate effects a great increase in the flow area. In the preferred embodiment, the plate itself is bimetallic whereas in an alternate embodiment, the plate is displaced angularly by a bimetallic element. Where the clearance space between the plate and the casing is problematical with respect to noise generation, the plate may be made rectangular and the sides of the casing where the plate engages may be parallel to one another.

13 Claims, 4 Drawing Figures wnzimiu 1 FIG.2

FIG.3

. 1 VALVE MEANS, PARTICULARLY AUTOMATIC WASTE GAS VALVE MEANS This invention relates to a valve means, particularly an automatic waste gas valve means, of the kind comprising an outer casing for connection, for example, to the waste gas pipe of a gas-fired apparatus and, respectively, a wall opening to a ventilation system, and further comprising an automatically operating temperature-sensitive member for throttling the free area of the valve means in response to the temperature.

Gas-fired water heaters in apartment houses, for example, give rise to ventilation problems. Primarily, the waste gases resulting from the combustion of the gas must be removed from the apartment. For this purpose the waste gas pipes of the water heaters mostly are connected to the control ventilation system in the apartment-house. This system usually comprises evacuation or throttle valve means adapted for passing therethrough stale air from the apartment to the atmosphere and constructed so as at a certain static pressure drop over the valve means to provide a definite air flow. Said valve means usually can be adjusted manually so as at the same pressure drop to change the air flow, and they mostly are given a fixed setting for the minimum ventilation requirement of the apartment in order to obtain the desired economy of operation.

The connecting of such gas-fired apparatus to the ventilation system involves the problem of bringing about temperature variations in the mixture of waste gas and air which is evacuated through the valve means to which the waste gas pipe is connected.

With conventional valve means, therefore, the amount by weight of waste gases evacuated when the apparatus is in opration will decrease at increasing temperature, due to a reduced density.

The requirement with respect to evacuation from a gas-fired apparatus, however, is that the waste gas amount evacuated shall be constant or possibly increase whenthe apparatus is in operation.

For solving the aforesaid problem, it was previously suggested to utilize an automatic valve means, which at the operation of the gas-fired apparatus enlarges the free passage area at increasingtemperatures.

Valve means of this kind not only involve certain shortcomings with respect to their function, but also show throughout the disadvantages of an unacceptably high natural sound production. This is the case at forced flow and often already at the basic ventilation flow.

The present invention has as its primary object to counteract, and to the greatest possible extent eliminate the aforesaid disadvantages.

This object is achieved by the valve means according to the invention which substantially is characterized in that the inlet of the valve means is formed by an at least partially conical or substantially conical surface with inward tapering, and that the temperature-sensitive member is a plate consisting preferably entirely or partially of bimetal or coacting with bimetal elements or the like, which plate is intended to expose a certain area for the basic flow and to maintain the weight of the passing gas amount constant or somewhat increasing at rising temperatures.

This solution renders it possible to maintain the weight of the evacuated waste gas amount constant or possibly somewhat increasing at increasing temperatures, at the same time as the valve means produces a low natural sound, which remains low even at a forced flow.

Further characterizing features of the invention and advantages obtained thereby become evident from the following detailed description, in which reference is made to the accompanying drawing, in which FIGS. 1 and 2 by way of an axial view and, respectively, a diametrical axial section show in a schematic way a preferred embodiment of a valve means according to the invention set for the basic flow, and

FIGS. 3 and 4 show in a schematic way a modified embodiment of a valve means according to the invention in a similar position and by similar views.

In order to facilitate the understanding of the Figures, particularly such details which extend all around are not shown in their entirety. Details being similar in both embodiments are given the same reference numerals.

The two embodiments shown, which generally are designated by l and 2, comprise an outer casing 3, which may consist of two co-axial sheet metal cylinders 5 and 6 connected to each other via two end flanges or the like 4. Of said cylinders, the cylinder adapted for connection to a waste gas pipe (not shown) of a gasfired apparatus, for example, has a diameter exceeding somewhat the diameter of the cylinder to be connected to a passageway within or an opening to a ventilation system. Of said end flanges or the like 4, one flange may advantageously transform into an inner reduction flange 7 extending all around, between the inner edge of which and the outer edge area of the cylinder 5 extends, for example, a conical surface 8 extending all around, which surface, thus, diverges in the direction to the gas-fired apparatus. The conicity, therefore, need not necessarily be mathematically accurate. One may also imagine an at least partial roundness, as indicated in FIG. 2. The inwardly tapered surface 8 includes an angle of preferably about 15 with an axial line. So far, the two embodiments are in agreement with each other.

At the embodiment according to FIGS. 1 and 2, the cylinder 5 is screened off in the direction to the gasfired apparatus by a wall 9, which seals against or is coherent with the adjacent outer edge area of said cylinder and which preferably terminates in the form of a straight edge at some distance from the centre axis of the cylinder. On the outside of said edge, a plate 10 is mounted with one longitudinal edge, for example via an intermediate bow 11, which plate entirely or partially is made of bimetal. Said plate 10 extends obliquely into and through the cylinder 5, intersecting thereby the centre axis preferably at the same angle, which the conical or tapered surface 8 covers with an axial line. Said plate is substantially plane and terminates with its free longitudinal edge preferably within the plane of the reduction flange 7. The two short sides converge in the direction to said free longitudinal edge in such a way, that the gap between the short sides and adjacent conical or tapered surface 8 is the smallest possible, with regard paid to the maximum movement of the plate in response to temperature. Said gap generally may be pretty small, for example about 5 mm at the free longitudinal edge of the plate 10. This entire movability area may be located outside the centre axis, for example beneath the dash-dotted line in FIG. 2. One may, of course, also choose another data of action, but the eccentric position shown in the drawings has proved to be highly advantageous with respect to natural sound production. The natural sound production being greatest at forced flow, the plate 10 and, respectively, conical surface may also be designed or arranged such that the gaps are greatest, for example about 1 mm, at the basic flow and insignificant at forced flow.

The free area of the valve means, thus, is formed by a circle segment, which preferably is smaller than a semicircle. Tests have shown that such a design, in connection with the aforedescribed characterizing features, brings about a highly satisfactory functioning of the valve means.

The details forming or framing the free area of the valve means are dimensioned for a certain basic flow, i.e., the relation between the inner diameter for the reduction flange and, respectively, the inner edge of the conical surface and the position of the plate are determined. A certain adjustment of the plate position may possibly be made by means of the bow 11 or other mounting means for the plate, so that the plate can assume different positions and thereby reduce or enlarge the free flow area. In this connection the conical surface may be formed by a separate member, which is rotatable in relation to the cylinder and comprises sections in the circumferential direction with varying angles of inclination, so that the conical surface always can be adjusted at optimum to the short sides of the plate in order to obtain as narrow gaps as possible and thereby to reduce or eliminate the production of natural sound in this area. For achieving the same object, the short sides of the plate may be formed of separate members with plane parallel movability in relation to the plate and mounted thereon. The adjustability obtained in this way is also at optimum, because the plate can assume different basic positions.

At rising temperature, i.e., normally when the gasfired apparatus starts to operate, the bimetal element turns the plate 10 about its mounting area to enlarge the free flow area. In the embodiment shown, the free longitudinal edge of the plate 10 is moved closer to the centre axis, but it does never reach the same. The low natural sound production of the valve means is maintained due to the relatively small change of said gaps. In this connection, and for the construction in general, it is important that the enlargement of the free area takes place from the basic ventilation area as the initial position, and that a relatively small movement of the plate effects a relatively great change of the free area.

Owing to the characterizing features described, a valve means has been obtained which combines the automatic .function, i.e. control, particularly maintaining constant, of the amount by weight of waste gas/air, with a low natural sound production in all positions. In other words, one has combined a device having a throttling correctly formed from a flow and sound technical point of view, and a movable member, which changes the appearance of the throttling not more than by changing the angle of inclination.

The embodiment according to FIGS. 3 and 4 differs from the aforedescribed embodiment, in that the throttling takes place by means of a plate 12 of preferably circle segment shape which is actuated by a bimetal element and mounted on the reduction flange 7 with the cylinder 6 by means of a bow or the like 13. The free pivotal plate edge preferably is provided with a guide strip 14. The strip edge exposed to the adjacent conical surface is bevelled, preferably with the same inclination angle as said conical or tapered surface. At rising temperature, the plate 12 with the strip 14 is bent in the direction to the outer central area of the cylinder 6, so that the free area is enlarged. The minimum and maximum free areas preferably agree with those in the embodiment first described.

The embodiments described above and shown in the drawing are to be considered only as non-restrictory examples, which may be modified in any optional way within the scope of the following claims. The temperature-sensitive elements, for example, need not necessarily consist of bimetal. Also other members temperature-sensitive per se may be utilized. Furthermore, neither the outer nor inner shape of the valve means must be circular-cylindric, but this shape is most advantageous with respect to different connection possibilities and general standard.

The relation described above may also be vice versa, viz, the gaps between the plate 10 and the conical surface are greatest at forced flow, because the total natural sound production in this phase usually is not increased appreciably through said gaps. The natural sound production through the gaps, on the other hand, can be of influence at the basic flow, and this influence is eliminated or reduced in the way now described.

The valve, as mentioned, must not have outer or inner circular-cylindric shape nor, respectively, the accurate shape of a truncated cone. lt may be advantageous in this connection to give the substantially conical surface 8 plane-parallel shape within the area for the two short sides of the plate. In this way the plate can have rectangular shape throughout and thereby render possible the reduction of said gaps to an absolute minimum size in all positions. The transition to the planeparallel sections can be effected by successively changing and, respectively, adjusting the angle of conicity.

The surface 8, of course, may also be placed within the secondary cylinder 6, seen in flow direction, and the wall 9 be adjustably attached on the reduction flange 7.

I claim:

1. A valve means comprising an outer casing having inlet and outlet means for connection to the waste gas pipe of a gas-fired apparatus and to a ventilation system, and an automatically operating temperaturesensitive bimetallic means for throttling the flow area of the valve means in response to the temperature, characterized in that the inlet of the valve means is formed by a transverse wall having a straight edge adjacent the center axis of the casing and an inwardly tapered surface, and that the temperature-sensitive bimetallic means includes a movable plate in the inlet in a position at one temperature to expose a certain area for the basic flow and in positions to increase the flow area to maintain the weight of the passing gas amount approximately constant or somewhat increasing at rising temperatures.

2. A valve means according to claim 1, characterized in that the casing is formed of two coaxial cylinders conncted to each other by end flanges, at least one of said end flanges being extended inwards to form an inner reduction flange preferably extending all around said casing.

3. A valve means according to claim 2, characterized in that the tapered surface extends from the free edge area of the reduction flange to the free edge area of the cylinder at the inlet.

4. A valve means according to claim 1 characterized in that the inlet end of said tapered surface is rounded and outwardly directed.

5. A valve means according to claim 1 characterized in that the angle of taper is about 6. A valve means according to claim 1, characterized in that said plate has one longitudinal edge connected adjacent the straight edge of the transverse wall, and that the plate extends obliquely into the casing at an angle relative to the axial direction of the casing which preferably is the same as for the tapered surface, the surface sections located in front of the plate forming an inwardly tapering inlet opening together with the plate.

7. A valve means according to claim 8, characterized in that the flow area of the inlet opening has the shape of a circle segment smaller than a semicircle.

8. A valve means according to claim 6 characterized in that said plate has a free longitudinal edge located adjacent the plane, within which the flow area is defined.

9. A valve means according to claim 1 characterized in that the plate intersects the center axis of the casing.

10. A valve means according to claim 1 characterized in that the plate has short sides so adjusted to the tapered surface to minimize the gaps formed upon maximum movement of the plate in response to temperature.

11. A valve means according to claim 8 characterized in that the movement of the plate is relatively small at the free longitudinal edge.

12. A valve means according to claim 1 characterized in that the plate has the shape ofa circle segment parallel to the plane in which the flow area is defined.

13. A valve means according to claim 12, characterized in that the free edge of the plate is provided with a guide strip, the edge of said strip exposed to the tapered surface being bevelled with the same angle of inclination as the tapered surface.

T p UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 7 2 27 Dated January 1, 191g lnv fl Stellan Akesson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading before [52] U.S Cl. the following should be added: Q

1 Foreign Application Priority Data April 19, 1971 Sweden 5008/1971 Signed arid sealed this 2nd day of July 19% (SEAL) Attest: EDWARD M.FLETCHER ,JR. T c. MARSHALL DANN Attesting Officer Commissioner of Patents O po'wso T T uscoMM-Dc scan-P69 i u,s. eovsnnuzu r rnm'mm orncz: 19a 0-365-334. j 

1. A valve means comprising an outer casing having inlet and outlet means for connection to the waste gas pipe of a gas-fired apparatus and to a ventilation system, and an automatically operating temperature-sensitive bimetallic means for throttling the flow area of the valve means in response to the temperature, characterized in that the inlet of the valve means is formed by a transverse wall having a straight edge adjacent the center axis of the casing and an inwardly tapered surface, and that the temperature-sensitive bimetallic means includes a movable plate in the inlet in a position at one temperature to expose a certain area for the basic flow and in positions to increase the flow area to maintain the weight of the passing gas amount approximately constant or somewhat increasing at rising temperatures.
 2. A valve means according to claim 1, characterized in that the casing is formed of two coaxial cylinders connected to each other by end flanges, at least one of said end flanges being extended inwards to form an inner reduction flange preferably extending all around said casing.
 3. A valve means according to claim 2, characterized in that the tapered surface extends from the free edge area of the reduction flange to the free edge area of the cylinder at the inlet.
 4. A valve means according to claim 1 characterized in that the inlet end of said tapered surface is rounded and outwardly directed.
 5. A valve means according to claim 1 characterized in that the angle of taper is about 15*.
 6. A valve means according to claim 1, characterized in that said plate has one longitudinal edge connected adjacent the straight edge of the transverse wall, and that the plate extends obliquely into the casing at an angle relative to the axial direction of the casing which preferably is the sAme as for the tapered surface, the surface sections located in front of the plate forming an inwardly tapering inlet opening together with the plate.
 7. A valve means according to claim 8, characterized in that the flow area of the inlet opening has the shape of a circle segment smaller than a semicircle.
 8. A valve means according to claim 6 characterized in that said plate has a free longitudinal edge located adjacent the plane, within which the flow area is defined.
 9. A valve means according to claim 1 characterized in that the plate intersects the center axis of the casing.
 10. A valve means according to claim 1 characterized in that the plate has short sides so adjusted to the tapered surface to minimize the gaps formed upon maximum movement of the plate in response to temperature.
 11. A valve means according to claim 8 characterized in that the movement of the plate is relatively small at the free longitudinal edge.
 12. A valve means according to claim 1 characterized in that the plate has the shape of a circle segment parallel to the plane in which the flow area is defined.
 13. A valve means according to claim 12, characterized in that the free edge of the plate is provided with a guide strip, the edge of said strip exposed to the tapered surface being bevelled with the same angle of inclination as the tapered surface. 